The green and golden bell frog (Litoria aurea) is an Australian hylid, which was once common with a relatively continuous distribution. Historically, this distribution extended from northern New South Wales (NSW), as far as Ballina, to East Gippsland in Victoria; with inland populations as far west as Bathurst and Tumut. Today the species is reported to have disappeared from 80% of its former range and remaining populations are mostly fragmented and typically restricted to the coastline, extending from Yuraygir National Park (northern NSW) to East Gippsland. In this thesis, I report a comprehensive study designed to identify the phylogeographic and conservation genetic parameters of L. aurea. In doing so, I also investigate evolutionary relationships within the ???bell frog??? species group. In this study, microsatellite and mitochondrial DNA (mtDNA) markers are employed. The development of species-specific microsatellite markers and the collection of samples was a substantial component of the study. These markers and samples should prove useful for future studies of L. aurea and perhaps more generally the ???bell frogs???. Initially, a large-scale assessment of genetic structure and diversity in L. aurea using microsatellite markers was undertaken. Twenty-one locations were sampled from throughout the species range covering 1000 kilometres of the east coast of Australia. Levels of allelic diversity and heterozygosity were high (uncorrected mean alleles/locus and HE: 4.8-8.8 and 0.43-0.8 respectively) compared to other amphibian species and significant differences among sampled sites were recorded. Despite recent population declines, no sites displayed a genetic signature indicative of a population bottleneck. Significant genetic structuring (overall FST = 0.172) was detected throughout the species range, but was relatively low compared to previous amphibian studies that used microsatellites. In addition, some areas sampled within continuous habitat showed evidence of weak genetic structuring (data subset FST = 0.034). Next, relationships among extant bell frogs (Litoria aurea species-group) were investigated, using mitochondrial ND4 nucleotide sequence data. Analyses supported a clade comprised of the temperate members of the species-group, L. aurea, L. cyclorhyncha, L. moorei, and L. raniformis but failed to support the inclusion of the tropical bell frog L. dahlii in this group. Relationships among the four members of the bell frog clade correlated with geographical distribution: the south-western Australian bell frogs (L. cyclorhyncha, L. moorei) and the south-eastern Australian bell frogs (L. aurea, L. raniformis) were reciprocally monophyletic. Results also indicated that divergence of these two lineages occurred during the late Miocene, which was consistent with results of previous studies and with more general assertions that much of the major differentiation and radiation of the Australian biota predated the Quaternary. Following this, intraspecific phylogeography of L. aurea using two mitochondrial genes COI and ND4 was investigated. I examined extant populations from throughout the species??? range, sequencing 263 individuals from twenty-six locations. Recent evolutionary history, as well as the current population structure of L. aurea, was inferred from the resulting pattern of genetic variation amongst haplotypes, in conjunction with demographic and population analyses. Results indicated that there were no phylogeographic divisions within L. aurea, despite a general consensus that amphibians are highly structured. However, I did still detect significant structure amongst extant populations (FST = 0.385). Overall, patterns of haplotype relatedness, high haplotypic diversity (mean h = 0.547) relative to low nucleotide diversity (mean Pi= 0.003), and mismatch distribution analysis supported a Pleistocene expansion hypothesis with continued restricted dispersal and gene flow. Taken together, the results of this thesis indicate that L. aurea is a species with relatively weak population and phylogeographic structure compared to other amphibians. The data provide no support for the existence of distinct evolutionary lineages within L. aurea, implying that there are no historically isolated populations that should be viewed as separate evolutionarily significant units. Nevertheless, remaining populations are still significantly structured but not all populations are genetically distinct. Low phylogeographic structure, coupled with evidence for recent gene flow among many sites would permit ???well managed??? intervention to mediate gene flow amongst currently isolated populations, and I provide some guidelines for the implementation of such conservation strategies. However, there is no evidence to suggest that supplementation through artificial immigration is at this time necessary given current levels of genetic variation within populations. In the short-term, conservation management in L. aurea should focus on the protection of local populations and habitat to promote population connectivity to ensure processes that maintain adaptive diversity and evolutionary potential are conserved. Preservation of the species??? natural range and the maintenance of dense networks of suitable habitat, in conjunction with maximising local carrying capacity and reproductive output, as well as minimising known threats, are key to securing the long-term persistence of the green and golden bell frog.

The green and golden bell frog (Litoria aurea) is an Australian hylid, which was once common with a relatively continuous distribution. Historically, this distribution extended from northern New South Wales (NSW), as far as Ballina, to East Gippsland in Victoria; with inland populations as far west as Bathurst and Tumut. Today the species is reported to have disappeared from 80% of its former range and remaining populations are mostly fragmented and typically restricted to the coastline, extending from Yuraygir National Park (northern NSW) to East Gippsland. In this thesis, I report a comprehensive study designed to identify the phylogeographic and conservation genetic parameters of L. aurea. In doing so, I also investigate evolutionary relationships within the ???bell frog??? species group. In this study, microsatellite and mitochondrial DNA (mtDNA) markers are employed. The development of species-specific microsatellite markers and the collection of samples was a substantial component of the study. These markers and samples should prove useful for future studies of L. aurea and perhaps more generally the ???bell frogs???. Initially, a large-scale assessment of genetic structure and diversity in L. aurea using microsatellite markers was undertaken. Twenty-one locations were sampled from throughout the species range covering 1000 kilometres of the east coast of Australia. Levels of allelic diversity and heterozygosity were high (uncorrected mean alleles/locus and HE: 4.8-8.8 and 0.43-0.8 respectively) compared to other amphibian species and significant differences among sampled sites were recorded. Despite recent population declines, no sites displayed a genetic signature indicative of a population bottleneck. Significant genetic structuring (overall FST = 0.172) was detected throughout the species range, but was relatively low compared to previous amphibian studies that used microsatellites. In addition, some areas sampled within continuous habitat showed evidence of weak genetic structuring (data subset FST = 0.034). Next, relationships among extant bell frogs (Litoria aurea species-group) were investigated, using mitochondrial ND4 nucleotide sequence data. Analyses supported a clade comprised of the temperate members of the species-group, L. aurea, L. cyclorhyncha, L. moorei, and L. raniformis but failed to support the inclusion of the tropical bell frog L. dahlii in this group. Relationships among the four members of the bell frog clade correlated with geographical distribution: the south-western Australian bell frogs (L. cyclorhyncha, L. moorei) and the south-eastern Australian bell frogs (L. aurea, L. raniformis) were reciprocally monophyletic. Results also indicated that divergence of these two lineages occurred during the late Miocene, which was consistent with results of previous studies and with more general assertions that much of the major differentiation and radiation of the Australian biota predated the Quaternary. Following this, intraspecific phylogeography of L. aurea using two mitochondrial genes COI and ND4 was investigated. I examined extant populations from throughout the species??? range, sequencing 263 individuals from twenty-six locations. Recent evolutionary history, as well as the current population structure of L. aurea, was inferred from the resulting pattern of genetic variation amongst haplotypes, in conjunction with demographic and population analyses. Results indicated that there were no phylogeographic divisions within L. aurea, despite a general consensus that amphibians are highly structured. However, I did still detect significant structure amongst extant populations (FST = 0.385). Overall, patterns of haplotype relatedness, high haplotypic diversity (mean h = 0.547) relative to low nucleotide diversity (mean Pi= 0.003), and mismatch distribution analysis supported a Pleistocene expansion hypothesis with continued restricted dispersal and gene flow. Taken together, the results of this thesis indicate that L. aurea is a species with relatively weak population and phylogeographic structure compared to other amphibians. The data provide no support for the existence of distinct evolutionary lineages within L. aurea, implying that there are no historically isolated populations that should be viewed as separate evolutionarily significant units. Nevertheless, remaining populations are still significantly structured but not all populations are genetically distinct. Low phylogeographic structure, coupled with evidence for recent gene flow among many sites would permit ???well managed??? intervention to mediate gene flow amongst currently isolated populations, and I provide some guidelines for the implementation of such conservation strategies. However, there is no evidence to suggest that supplementation through artificial immigration is at this time necessary given current levels of genetic variation within populations. In the short-term, conservation management in L. aurea should focus on the protection of local populations and habitat to promote population connectivity to ensure processes that maintain adaptive diversity and evolutionary potential are conserved. Preservation of the species??? natural range and the maintenance of dense networks of suitable habitat, in conjunction with maximising local carrying capacity and reproductive output, as well as minimising known threats, are key to securing the long-term persistence of the green and golden bell frog.

Many freshwater mussels are imperiled, due to a number of interrelated factors such as habitat alteration, degradation of water quality, and impoundments. The Golden Orb mussel (Quadrula aurea, I. Lea, 1859) is endemic to the state of Texas and is currently a candidate for the endangered species list, as the number of known populations has been declining in recent years. Little is currently known about Q. aurea aside from basic distribution data. This study is focused on evaluating a combination of macro-habitat and micro-habitat variables to determine their influence on the distribution and density of this species. Macro-habitat variables, including dominant land cover, surface geology, and soil erodibility factor, did not have a significant relationship with mussel distributions. The best model of micro-habitat variables that impacts the Q. aurea distributions is comprised of relative substrate stability (RSS) at moderate flows and current velocity at low flows. For all mussel species in this study, current velocity at low flows is the primary variable that influences distribution. Q. aurea are associated with habitats where larger sediment particles (large gravel and cobble) help to stabilize the substrate in areas with higher current velocities. An understanding of the preferred habitats for Q. aurea can be used to help focus conservation efforts and practices.

Made available in DSpace on 2016-08-10T10:38:33Z (GMT). No. of bitstreams: 1 FERNANDA FRAGA ROSA.pdf: 781807 bytes, checksum: c1ba382ad100630630a5f0f78ae880f8 (MD5) Previous issue date: 2011-08-12 / Tabebuia aurea is a tree widely distributed in the Cerrado and that is subject to the deleterious effects of fragmentation of this biome. In this work, were studied 237 samples from 12 populations of Tabebuia aurea based on the variation of 11 microsatellite loci, in order to analyze the genetic diversity and structure and test the causes of differentiation of populations. Tabebuia aurea has high genetic diversity in all populations with 379 alleles found an average of 34.4 alleles per locus, the population had an overall average of 11.89 alleles revealing a high information content associated with microsatellite markers. The average values of expected heterozygosity (He) and observed (Ho) found for the loci were 0.894 and 0.692 respectively. The inbreeding coefficient within populations ranged from 0.075 to 0.337 at the EGM in PAN, all figures are significant, P <0.00038 with a confidence interval of 95%, indicating that the allele frequencies are not following the expected proportions for balance Hardy- Weinberg equilibrium, namely, what is occurring mating between related individuals. The population of the Ecological Station of Águas Emendadas (AGE), in permanent preservation area, showed the greatest genetic diversity. The other populations in areas of permanent preservation, Emas National Park (ENP) and the APA Rio Pandeiros (PAN), did not show greater genetic diversity than other areas in the agricultural matrix fragments. However, the inbreeding coefficient was higher in areas most affected by human disturbances when compared to the conservation area. The differentiation between populations is low, but significant (&#952; = 0.061, P = 0.0005), (F = 0.264, P = 0.0005) (f = 0.216, P = 0.0005). &#920; values were lower than those of values RST, indicating that the alleles are more likely to be identical by descent by state. The pattern of genetic isolation by distance was tested by correlating the genetic distance matrix with the matrix of geographical distance and was inefficient for the discrepancy found between populations. The non-random mating tooth and between populations, the distribution pattern of T. aurea in groups and pollination at short distance, probably are the factors responsible for genetic structure in T. aurea. / Tabebuia aurea é uma espécie arbórea de ampla distribuição no Cerrado que está sujeita aos efeitos deletérios da fragmentação deste bioma. Neste trabalho, foram estudadas 237 amostras de 12 populações de Tabebuia aurea com base na variação de 11 locos microssatélites, com o objetivo de analisar a diversidade e estrutura genética e testar as causas da diferenciação das populações. Tabebuia aurea possui alta diversidade genética em todas as populações com 379 alelos encontrados, uma média de 34,4 alelos por loco, as populações apresentaram uma média geral de 11,89 alelos revelando um elevado conteúdo informativo associado aos marcadores microssatélites. Os valores médios de heterozigosidade esperada (He) e observada (Ho) encontrados para os locos foram de 0,894 e 0,692 respectivamente. O coeficiente de endogamia dentro das populações variou de 0,075 em AGE a 0,337 em PAN, todos os valores são significativos, P < 0,00038 com intervalo de confiança de 95%, indicando que as frequências alélicas não estão seguindo as proporções esperadas para o equilíbrio de Hardy-Weinberg, ou seja, que está ocorrendo o acasalamento entre indivíduos aparentados. A população da Estação Ecológica de Águas Emendadas (AGE), em área de preservação permanente, apresentou a maior diversidade genética. As outras populações em áreas de preservação permanente, Parque Nacional das Emas (PNE) e APA do Rio Pandeiros (PAN), não apresentaram maior diversidade genética que as demais áreas em fragmentos de matriz agrícola. Entretanto, o coeficiente de endogamia foi maior nas áreas mais afetadas por distúrbios antrópicos quando comparado à área de conservação. A diferenciação entre populações é baixa, porém significativa ( q = 0,061; P = 0,0005), (F = 0,264, P = 0,0005) (f = 0,216; P = 0,0005). Os valores de q foram inferiores aos valore de RST, indicando que os alelos são mais propensos a serem idênticos por estado que por descendência. O modelo de isolamento genético por distância foi testado, correlacionando a matriz de distância genética com a matriz de distância geográfica e se mostrou ineficiente para a divergência encontrada entre as populações. Os acasalamentos não aleatórios dentro e entre as populações, o padrão de distribuição de T. aurea em grupos e a polinização a curta distância, provavelmente são os fatores responsáveis pela estrutura genética em T. aurea.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Habilitationsschrift--Halle.

Habilitationsschrift--Halle.

No description available.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2018-04-09T14:42:24Z No. of bitstreams: 2 Dissertação - Lucas Donizetti Vieira - 2018.pdf: 2934046 bytes, checksum: 50730e1b6711826aafed66d22a56852f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-04-09T14:44:18Z (GMT) No. of bitstreams: 2 Dissertação - Lucas Donizetti Vieira - 2018.pdf: 2934046 bytes, checksum: 50730e1b6711826aafed66d22a56852f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-04-09T14:44:18Z (GMT). No. of bitstreams: 2 Dissertação - Lucas Donizetti Vieira - 2018.pdf: 2934046 bytes, checksum: 50730e1b6711826aafed66d22a56852f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-03-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Population genomics studies in Neotropical species are scarce, however, they are of great importance for the understanding of the neutral and adaptive variations, in order to develop strategies of management and conservation for the species. In this context our objective was to verify the role of natural selection in the distribution of populations diversity in Handroanthus serratifolius and Tabebuia aurea. Here, we study population genomics based in sequence capture using 24,751 pre-developed probes. For H serratifolius were sampled c. 64,000 SNPs in 144 individuals from 16 populations. For T aurea were sampled c. 18,000 SNPs in 48 individuals from 6 populations. Genetic differentiation was high (FST = 0.194, p <0.001) in H. serratifolius and intermediate (FST = 0.144, p <0.001) in T. aurea. The inbreeding coefficient was low in both species, however, in three populations of H. serratifolius it was intermediate or high. The genetic structure of populations presented two genetic groups for the populations sampled in the two species. H. serratifolius with high genetic differentiation and T. aurea with admixture in all populations. We did not find SNPs outliers in the distribution of FST values, due to the wide distribution of values found for the populations of the two species. In the search for correlation between environmental variables and changes in allelic frequency H. serratifolius presented only three SNPs, inside six genes and T. aurea presented 16 SNPs, inside 25 genes. The functional annotation of these genes showed relationship with molecular processes, transposable elements and one in T. aurea related to resistance to diseases. In conclusion, our data show a selection signal in H. serratifolius for only three loci with local adaptation signal. In T. aurea our data show a greater number of locos (16 locos) with local adaptation signal. / Estudos de genômica de populações em espécies Neotropicais são escassos, no entanto, apresentam grande importância para o entendimento das variações neutras e adaptativas, a fim de desenvolver estratégias de manejo e conservação das espécies. Nesse contexto nosso objetivo foi verificar o papel da seleção natural na distribuição da diversidade de populações de Handroanthus serratifolius e Tabebuia aurea. Aqui, nós estudamos a genômica de populações baseado em sequence capture utilizando 24.751 sondas previamente desenvolvidas. Para H serratifolius foram amostrados c. 64.000 SNPs em 144 indivíduos de 16 populações. Para T aurea foram amostrados c. 18.000 SNPs em 48 indivíduos de 6 populações. A diferenciação genética foi alta (FST = 0,194, p < 0,001) em H. serratifolius e intermediária (FST = 0,144, p < 0,001) em T. aurea. O coeficiente de endogamia foi baixo nas duas espécies, no entanto, em três populações de H. serratifolius foi intermediária ou alta. A estrutura genética das populações apresentou dois grupos genéticos para as populações amostradas nas duas espécies. H. serratifolius com alta diferenciação genética e T. aurea com mistura em todas as populações. Nós não encontramos SNPs outliers na distribuição de valores de FST, devido a ampla distribuição de valores encontrada para as populações das duas espécies. Na busca por correlação entre variáveis ambientais e mudanças na frequência alélica H. serratifolius apresentou apenas três SNPs, presentes em seis genes e T. aurea apresentou 16 SNPs, presentes em 25 genes. A anotação funcional desses genes mostrou relação com processos moleculares, elementos transponíveis e um em T. aurea ligado a resistência a doenças. Concluindo, nossos dados apresentam sinal de seleção em H. serratifolius para apenas três locos com sinal de adaptação local. Em T. aurea nossos dados mostram maior número de locos (16 locos) com sinal de adaptação local.

Made available in DSpace on 2015-05-14T12:59:25Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 799830 bytes, checksum: e9ce4907eb8193bacb26ea198ef6011e (MD5) Previous issue date: 2011-02-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The Topoisomerase II is involved in several vital cellular processes such as replication and transcription of DNA, in addition to the segregation of chromosomes. This enzyme catalyzes changes in DNA topology by temporary disruptions and subsequent rearrangement of the double helix and is essential for cell proliferation to occur. Many compounds that interfere with the catalytic activity of this enzyme are effective in chemotherapy of cancer. The development of new inhibitors from plant sources can be a valuable strategy, serving also as a tool for the production of semi-synthetic active agents that do not cause serious damage to the body and with a lower cost. Has already been reported that some lignoids derived from plants have inhibitory action on DNA Topoisomerase II. Plants of the Lauraceae family are sources of bioactive lignoids. Among different species, there are the Licaria aurea and Licaria chrysophylla. In this study, 12 lignoids derived from both species were evaluated for their inhibitory effect on human DNA Topoisomerase II, using etoposide as action control of substances. Two of these compounds showed inhibitory activity against the human enzyme Topoisomerase II. These compounds are the lignan (2S,3S)-Dihydro-dehydrodiconiferyl alcohol-3-(&#61538;-D-glycopiranosyl)-hexaacetate and the neolignan 1,4-Bis-(3, 4,5-trimethoxyphenyl)-2,3-dimethylbutane. / A Topoisomerase II está envolvida em diversos processos celulares vitais, como a replicação e a transcrição do DNA, além da segregação dos cromossomos. Essa enzima catalisa mudanças na topologia do DNA através de rupturas temporárias e posterior rearranjo da dupla hélice, sendo fundamental para que ocorra a proliferação celular. Muitos compostos que interferem na atividade catalítica dessa enzima são eficientes no tratamento quimioterápico de câncer. O desenvolvimento de novos inibidores a partir de fontes vegetais pode ser uma estratégia valiosa, podendo servir também como um instrumento adequado para a produção de agentes ativos semi-sintéticos que não causem danos graves ao organismo e que apresentem um menor custo. Já se tem reportado que alguns lignóides derivados de plantas têm ação inibitória sobre a DNA Topoisomerase II. Plantas da família Lauraceae são fontes de lignóides bioativos. Dentre as diversas espécies, encontra-se a Licaria aurea e a Licaria chrysophylla. No presente estudo, 12 lignóides derivados destas duas espécies foram avaliados quanto à sua capacidade inibitória sobre a DNA Topoisomerase II humana, utilizando a etoposida como controle de ação das substâncias. Dois dos compostos estudados apresentaram atividade inibitória sobre a enzima Topoisomerase II humana. Esses compostos são a lignana (2S,3S)-Dihidro-dehidrodiconiferil alcool-3-(&#61538;-D-glicopiranosil)-hexaacetate e a neolignana1,4-Bis-(3, 4,5-trimetoxifenil)-2,3-dimetilbutano.